This invention relates to a POS system and to a method for operating a POS system.
Such a POS system comprises a checkout means for carrying out a payment operation and a cash drawer with a storage compartment for storing money. In an open condition of the cash drawer, the storage compartment is open, so that money can be put into the storage compartment or can be taken from the storage compartment. In a closed condition of the cash drawer, the storage compartment is closed, so that an access to money in the storage compartment is not possible. There is provided a control means for controlling the cash drawer, in that in particular in the event of predetermined conditions the control means generates a control signal for opening the cash drawer. By means of a sensor means it can then be detected whether the cash drawer is open, wherein the sensor means is formed to generate an opening signal which indicates whether the cash drawer is in its open condition.
In a POS system in the form of an electronic cash register, which is known from DE 34 07 674 C2, there is provided a control means in the form of a central processing unit (CPU) which outputs a command to a drive for automatically opening a cash drawer. The control means is formed to initiate an opening operation, when after the registration of goods a payment operation is to be made, during which an operator for example takes cash from the cash drawer and gives the same to a customer. The cash drawer subsequently is manually closed by the operator.
In a conventional POS system, a payment operation generally is made such that an operator registers goods and by means of a suitable reader for example reads in bar codes applied to goods or manually enters goods identifiers into an input device of the POS system. After registration of the goods, the control means generates a control signal for opening the cash drawer, which thereupon is opened automatically, so that the operator can put money into the storage compartment of the cash drawer or take money from the storage compartment. After the payment operation, the cash drawer is manually closed by the operator, so that a further payment operation can be initiated.
In conventional POS systems it is detected by means of a sensor means whether the cash drawer also has correctly been closed again after carrying out a payment operation. For this purpose, the sensor means for example can generate an opening signal in the form of an increased sensor signal level, which is present as long as the cash drawer is open. When the opening signal decreases, it can be inferred therefrom that the cash drawer has been closed.
In such POS systems a manipulation eventually is possible in that a foreign object is brought in contact with the sensor means formed for example as microswitch or microcontact and thereby a closed cash drawer is feigned, so that the opening signal of the sensor means decreases. Although the sensor signal hence indicates a closed cash drawer, the cash drawer in reality still is open, without this being detected by the POS system. With open cash drawer, a manipulator then can access to money present in the cash drawer.